1. Field of the Invention
The present invention relates to electronic equipment or an electronic device, and more particularly to electronic equipment accommodated in a case and that may be externally mounted on a main electronic apparatus by a screw member.
2. Description of the Prior Art
When an exchangeable ROM unit as an expansion electronic device is to be externally mounted on a main electronic apparatus such as an electric typewriter or a personal computer, it is necessary that the ROM unit be provided with a shield effect for shielding noise. If a case of such a unit has no noise shielding function, it is necessary to attach a separate shield plate to the case and electrically connect the shield plate to the typewriter body to ground it.
In mounting such a ROM unit on the electric typewriter, a screw member has been used.
However, in electronic equipment and devices such as a ROM unit which are to be externally mounted on the main electronic apparatus by the screw member, the screw member is frequently dropped and lost when the electronic device is exchanged. Further the shield plate must be grounded to the main electronic apparatus at each exchange.